Sheet Feeding Device Having Skew Calibration

ABSTRACT

A sheet feeding device having skew calibration which is disposed at a feeding end of a business machine. The sheet feeding device includes a driving module, a feeding module and a differential speed module. The sheet feeding device utilizes the differential speed module to provide the driving power transmitted from the driving module to two feeding rollers of the feeding module respectively, and utilizes the friction difference between these different feeding rollers to change the rotating speed or the rotating direction of the feeding rollers, so as to achieve the objective of actively calibrating the skewed sheet.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Taiwan Patent Application No.103213698, filed on Aug. 1, 2014, in the Taiwan Intellectual PropertyOffice, the disclosure of which is incorporated herein in its entiretyby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a sheet feeding device, moreparticularly, to a sheet feeding device capable of utilizingdifferential speed device to solve the problem of skewed sheet duringfeeding.

2. Description of the Related Art

In order to meet the requirement for mass sheet operation, a commonscanner, printer or multi-function printer on market usually has anautomatic document feeder. The user can put a stack of sheets in theautomatic document feeder, which will feed the sheets into the machinesequentially for performing scan, print, etc. If the user does notadjust the sheets to a correct position, or the sheet is skewed duringfeeding process, the printed or scanned image is skew. Therefore, theautomatic document feeder usually has a special calibration scheme tocorrect the skewed sheet to decrease the skew degree of printed orscanned image before the sheet is fed into the work area of scan orprint.

In traditional solution, a common approach is to utilize at least twomotors incorporating with a clutch or a solenoid valve to perform activede-skew operation, so a speed difference between different feedingrollers can be controlled to calibrate the skewed sheet. However, itneeds an extra time for the motor to drive the feeding roller from stopto rolling, and it also adds extra time to change driving direction, sothe required time for operation of scan or print is increased. Moreover,frequently changing driving direction and rotation speed of the motor iseasy to damage the actuator and the controller, so the lift time of thefeeding device is reduced.

In addition, using many motors for calibration easily has problems ofcontrol error caused by signal delay, increased cost caused by manyassociated assemblies, hard to miniaturization due to large volumeoccupied by the motors.

SUMMARY OF THE INVENTION

An exemplary embodiment of the present disclosure provides a sheetfeeding device having skew calibration which utilizes a differentialspeed mechanism to drive the rotating speeds of two feeding rollers,respectively, so as to vary the rotating speed or rotating direction bythe friction difference between different feeding rollers. Therefore,the active calibration can be achieved.

An exemplary embodiment of the present disclosure provides a sheetfeeding device having skew calibration which utilizes engagement betweengears of the differential speed mechanism to transmit driving powerefficiently, so as to decrease the possibility of the systeminvalidation caused by signal delay or electric invalidation which isoccurred easily while a motor controller is used.

According to one exemplary embodiment of the present disclosure, a sheetfeeding device having skew calibration is disposed at a feeding end of abusiness machine. The sheet feeding device includes a driving module, afeeding module and a differential speed module. The driving moduleincludes a power source and a driving transmission unit, and the drivingtransmission unit is linked to the power source. The feeding moduleincludes a first feeding roller and a second feeding roller, and isdisposed at the feeding end to feed a plurality of sheets into thebusiness machine. The differential speed module includes a differentialspeed mechanism, a first output shaft and a second output shaft. Thedifferential speed mechanism can be linked to the driving transmissionunit to drive the first output shaft and the second output shaft. Thefirst output shaft and the second output shaft are disposed at two sidesof the differential speed mechanism respectively. The first output shaftand the first feeding roller are linked with each other, and the secondoutput shaft and the second feeding roller are linked with each other.Preferably, the differential speed module utilizes a friction differencegenerated by the first feeding roller and the second feeding rollerduring the sheet feeding, to enable the first feeding roller and thesecond feeding roller to rotate at the same direction or differentdirections, so as to actively calibrate the plurality of sheets skewed.

Preferably, the driving transmission unit includes a gear set or atiming belt assembly.

Preferably, the differential speed mechanism includes a planetary gearset, a bevel gear set or a combination thereof.

Preferably, the first feeding roller and the second feeding roller arearranged coaxially.

Preferably, the differential speed module further includes a torqueadjusting unit to adjust a torque required for driving the operation ofthe differential speed mechanism.

Preferably, the feeding module further includes a stopper to constrain askew range of a plurality of sheets.

Preferably, the rotating speeds of the first feeding roller and thesecond feeding roller can be the same or different.

Preferably, the surfaces of the first feeding roller and the secondfeeding roller further include guiding surfaces to facilitate feeding ofthe plurality of sheets.

Preferably, the guiding surface includes small-scale bumpy structures.

Preferably, the guiding surface can be a rough surface.

Objectives of the present disclosure are to provide a sheet feedingdevice having skew calibration which has the following advantages:

1. Active skew calibration: the differential speed mechanism is utilizedto drive two individual feeding rollers to rotate at the same directionor different directions, so as to actively correct the skewed sheetbased on a friction difference between two feeding rollers.

Therefore, the sheets can be fed into the business machine smoothly.

2. low invalidation possibility: compared with the traditional deviceusing an electric controller to control and drive motor, thedifferential speed mechanism has sufficient mechanism accuracy tomaintain rotation efficiency for a long period of time, and theinvalidation possibility that stall, slip or delay occurred betweenmechanism devices is lower than electric invalidation.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed structure, operating principle and effects of the presentdisclosure will now be described in more details hereinafter withreference to the accompanying drawings that show various embodiments ofthe present disclosure as follows.

FIG. 1 is a schematic view of sheet feeding device having skewcalibration of the present disclosure.

FIG. 2 is an operational schematic view of the sheet feeding devicehaving skew calibration of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Therefore, it is to be understood that theforegoing is illustrative of exemplary embodiments and is not to beconstrued as limited to the specific embodiments disclosed, and thatmodifications to the disclosed exemplary embodiments, as well as otherexemplary embodiments, are intended to be included within the scope ofthe appended claims. These embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey theinventive concept to those skilled in the art. The relative proportionsand ratios of elements in the drawings may be exaggerated or diminishedin size for the sake of clarity and convenience in the drawings, andsuch arbitrary proportions are only illustrative and not limiting in anyway. The same reference numbers are used in the drawings and thedescription to refer to the same or like parts.

It will be understood that, although the terms ‘first’, ‘second’,‘third’, etc., may be used herein to describe various elements, theseelements should not be limited by these terms. The terms are used onlyfor the purpose of distinguishing one component from another component.Thus, a first element discussed below could be termed a second elementwithout departing from the teachings of embodiments. As used herein, theterm “or” includes any and all combinations of one or more of theassociated listed items.

Please refer to both of FIG. 1 and FIG. 2 which are schematic view andoperational schematic view of a sheet feeding device having skewcalibration of the present disclosure. The sheet feeding device havingskew calibration 100 is disposed at a feeding end (not shown in FIGs) ofa business machine and includes a driving module 10, a feeding module 20and a differential speed module 30. The driving module 10 includes apower source 11 and a driving transmission unit 12 which is linked tothe power source 11. In implementation, the power source 11 may be anactuator such as a motor, and the driving transmission unit 12 can be agear set or a timing belt assembly. Furthermore, the gear set can beselected from spur gear set, bevel gear set and hypoid gear setaccording to a direction difference between the transmission shaft andthe output shaft. The business machine includes a scanner, a printer ora multi-function printer.

The feeding module 20 includes a first feeding roller 21 and a secondfeeding roller 22, and is disposed at a feeding end to feed a pluralityof sheets 8 into the business machine. In implementation, the firstfeeding roller 21 and the second feeding roller 22 are arrangedcoaxially to perform a smooth feeding operation. Moreover, the feedingmodule 20 can further be added a stopper 25 on a sheet depositingstructure to constrain the skew range of a plurality of sheets 8. Thestopper 25 can be a guarding plate or an adjustable clamping device.

For further illustration, the surfaces of the first feeding roller 21and second feeding roller 22 can be performed a surface roughnessprocess or be added small-scale bumpy structures, so the guidingsurfaces 28 with different roughness are utilized to increase thesurface friction for facilitating to feed the sheet 8.

The differential speed module 30 includes a differential speed mechanism31, a first output shaft 32 and a second output shaft 33. Thedifferential speed mechanism 31 can be linked to the drivingtransmission unit 12 to drive the first output shaft 32 and the secondoutput shaft 33. The first output shaft 32 and the second output shaft33 are disposed at two sides of the differential speed mechanism 31respectively. The first output shaft 32 and the first feeding roller 21are linked with each other, and the second output shaft 33 and thesecond feeding roller 22 are linked with each other.

The differential speed module 30 utilizes the friction differencegenerated by the first feeding roller 21 and the second feeding roller22 during the sheet feeding, to enable the first feeding roller 21 andthe second feeding roller 22 to rotate at the same direction ordifferent directions, so as to actively calibrate the skew sheet 8caused by improper placement. In implementation, the differential speedmechanism 31 can include a planetary gear set, bevel gear set or thecombination thereof. The differential speed module 30 can furtherinclude a torque adjusting unit 35 to adjust the torque which isrequired to drive operation of the differential speed mechanism 31.

For example, during the sheet feeding process, the feeding module 20directly receives the driving power transmitted from the driving module10, to drive the first feeding roller 21 and the second feeding roller22 to rotate at the same direction and the same speed.

When the sheet 8 is skewed due to improper placement, a side of thesheet 8 is contacted with the second feeding roller 22 first, and africtional resistance is generated on the second feeding roller 22 tomake the rotating speed of the second feeding roller 22 decrease, in themeantime, the differential speed module 30 transmits the driving powerto the side having smaller friction to increase the rotating speed ofthe first feeding roller 21, so that the sheet 8 can be corrected theskew angle gradually, and fed into the business machine smoothly.

The sheet feeding device of the present disclosure utilizes thedifferential speed module to provide the driving power transmitted fromthe driving module to two feeding rollers of the feeding module,respectively, and utilizes the friction difference between thesedifferent feeding rollers to change the rotating speed or rotatingdirection of the feeding rollers, so as to achieve the objective ofactively calibrate the skew sheet.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present disclosure, without any intention to limit thescope of the present disclosure thereto. Various equivalent changes,alternations or modifications based on the claims of present disclosureare all consequently viewed as being embraced by the scope of thepresent disclosure.

1. A sheet feeding device having skew calibration, disposed in a feeding end of a business machine, the sheet feeding device comprising: a driving module, comprising a power source and a driving transmission unit, the driving transmission unit linked to the power source; a feeding module, comprising a first feeding roller and a second feeding roller, and disposed at the feeding end to feed a plurality of sheets into the business machine; and a differential speed module, comprising a differential speed mechanism, a first output shaft and a second output shaft, and the differential speed mechanism linked to the driving transmission unit to drive the first output shaft and the second output shaft, and the first output shaft and the second output shaft disposed at two sides of the differential speed mechanism respectively, and the first output shaft and the first feeding roller linked with each other, and the second output shaft and the second feeding roller linked with each other; wherein the differential speed module utilizes the friction difference generated by the first feeding roller and the second feeding roller during the sheet feeding, to enable one of the first feeding roller and the second feeding roller having a smaller friction to increase a rotating speed, so as to actively calibrate the plurality of sheets skewed.
 2. The sheet feeding device having skew calibration according to claim 1, wherein the driving transmission unit comprises a gear set or a timing belt assembly.
 3. The sheet feeding device having skew calibration according to claim 1, wherein the differential speed mechanism comprises a planetary gear set, a bevel gear set or a combination thereof.
 4. The sheet feeding device having skew calibration according to claim 1, wherein the first feeding roller and the second feeding roller are arranged coaxially.
 5. The sheet feeding device having skew calibration according to claim 1, wherein the differential speed module further comprises a torque adjusting unit to adjust a torque required to drive the operation of the differential speed mechanism.
 6. The sheet feeding device having skew calibration according to claim 1, wherein the feeding module further comprises a stopper to constrain a skew range of the plurality of sheets.
 7. The sheet feeding device having skew calibration according to claim 1, wherein the rotating speeds of the first feeding roller and the second feeding roller are the same or different.
 8. The sheet feeding device having skew calibration according to claim 1, wherein each of the first feeding roller and the second feeding roller further has a guiding surface on surface thereof, to facilitate the feeding of the plurality of sheets.
 9. The sheet feeding device having skew calibration according to claim 8, wherein the guiding surface comprises small-scale bumpy structures.
 10. The sheet feeding device having skew calibration according to claim 8, wherein the guiding surface is a rough surface. 